Safety attachment for aeroplanes



April 25, 1933.

c. A. BOLCOM 1,905,337

SAFETY ATTACHMENT FOR AEROPLANES Filed Aug. 3, 1931 2 Sheets-Sheet 1 g'wwz'nto'c Clarence/5130100172 attozwm April 25, 1933. c A. BOLCOM SAFETY ATTACHMENT FOR AEROPLANES Filed Aug. 5, 1931 2 Sheets-Sheet 2 fllarence 14130100171 Patented Apr. 25, 1933 UNITED STATES GLARENGE A. IBOLCOM, OF- IONIA, MICHIGAN SAFETY ATTACHMENT FOR AEROPLANES Application filed August 3, 1931. Serial No. 554,867.

My invention relates to a safety attachment for aeroplanes.

The essential objects of my invention are to provide, in a manner as hereinafter set forth, means for retarding the descent of an aeroplane when the latter becomes damaged or the motor thereof stalls whereby the ves-' sel can land without injury thereto or to the occupants thereof; an attachment for the purpose intended capable of being expeditiously shifted to retarding position when occasion requires; to provide for the gradual descent of an aeroplane when desired resulting in the saving of life and to prevent damage to the vessel; and to attain these ends in a strong, durable compact, thoroughly eflicient, readily installed and comparatively inexpensive structure. 7

To the above ends essentially my invention consists in such parts and such combination of parts as fall within the scope of the invention as claimed.

In the drawings Figure 1 is a side elevation, broken away, of an aeroplane showing the adaptation therewith of a safety attachment in accordance with this invention. 1

Figure 2 is a fragmentary view in top plan of an aeroplane showing the retarding elements of the attachment in non-active posi tion.

Figure 3 is an elevation, partly in section of the safety attachment.

Figure 4 is a section on line H Figure 3.

Figure 5 is a section on line 55 Figure 3.

The attachment includes a pair of normally latched rotatable shafts, each providedwith and bodily carryinga horizontally disposed retarder element. The retarder elements, when the shafts are latched being in superposed parallel relation. The attachment also includes means for releasing the shafts and for rotating one relatively to the other to position the retarder elements in cross wise relation and at right angles to each other whereby when in such position the atmospheric pressure acting upon the retarder elements will revolve them horizontally. The

retarder elements when revolving will function to sustain the aeroplane in a manner so that the descent thereof will be gradual.

Referring to the drawings, l denotes the fuselage, 2 the cockpit, 3 the propeller and i the landing gear of an aeroplane 5. I

There is'illustrated by way of example, one embodiment of the invention for the object. sought and which-includes a vertically disposed rotatable tubular outer shaft 6 arranged forwardly of the cockpit 2" and extending the required distance above the top of fuselage 1. The shaft 6 is suitably connected to and sustained in the desired manner in fuselage 1. The upper end of shaft 6 is reduced, as at 7 and fixedly secured to the reduced upper end 7 of shaft 6 is a retarding element 8 in the form of a duplex propeller blade 9, and the latter has its upper face in proximity to the point of joinder with shaft 6 formed with a lug 10 for a purpose to be presently referred to.

Extending through the shaft 6 is an inner shaft 11 carrying on its upper end a retard ing element 12 in the form of a duplexpro- 7 peller blade 13. The periphery of the shaft 11at its upper end is formed with a tangentially disposed arm 14 which coacts with the lug 10 for a purpose to be presently referred to. The lug 10 is arranged in the pathof arm 14. The lower end of shaft 11 is provided with a beveled pin tooth pinion 15 which meshes with a beveled gear 16 carried by the lower end of a rotatably mounted shaft 17 provided with a ratchet wheel 18.

The shafts 6 and 11 have coacting clutching means, as at 19 for normally latching them from movement, and when latched the retarding elements 8 and 12 are arranged in superposed parallel spaced relation.

A pull member 20 is engageable with ratchet wheel 18 for the'purpose of rotating shaft 17 to cause the unclutching of shafts 6 and 11 and the rotation of the latter to position element 12 transversely across the center of element 8 and at right anglesthereto. When shaft 11 is rotated arm 1 f will abut lug 10 and arrest movement of shaft 11 relative to shaft 6. The device is now in active'position. Atmospheric pressure acting on blades 9 and 13 will revolve them and will sustain the aeroplane in a manner to provide for the gradual descent thereof. The shafts 6 and 11 will operate in unison during the revolving of the blades 9 and 13.

The pull member 20 is operated from a lever arm 21 which has its lower end pivotally connected to a bracket 22.

The pull member 20 when shifted to initially rotate shaft 11 will be moved clear of ratchet wheel 18 whereby the operation of shaft 17 is not interfered with when driven from shaft 11, pinion 15 and gear 16.

What I claim is 1. A safety attachment for aeroplanes comprising an inner and an outer rotatable shaft, the former extending above the latter, an atmospheric pressure revoluble retarder element fixed to the upper end of each of said shafts, said shafts having automatically operable coacting means intermediate their ends for normallylatching said shafts from movement to maintain said elements in superposed parallel spaced stationary relation,

rotatable means operatively engaging with r the lower end of said inner shaft for initially rotating such shaft to position the retarder element carried thereby transversely across and at right angles to the other of said elements whereby said elements are positioned to be revolved by atmospheric pressure, and the upper end of said inner shaft and central portion of that element carried by the outer shaft having coacting means to provide for 'said shafts operating in unison on the revolving of said elements and for retaining said elements at right angles to each other.

2. A safety attachment for aeroplanes comprising an inner and an outer rotatable shaft, the former extending above the latter, an atmospheric pressure revoluble retarder element fixed to the upper end of each of said shafts, said shafts having automatically oprable coacting means intermediate their ends'for normally latching said shafts from movement to maintain said elements in superposed parallel spaced stationary relation, rotatable means operatively engaging with the lower end of said inner shaft for initially rotatingsuch shaft to position the retarder element carried thereby transversely across and at right angles to the other of said elements whereby said elements are positioned to be revolved by atmospheric pressure, and means to provide for said shafts operating in unison on the revolving-of said elements and for maintaining said elements at right angles to each other;

In testimony whereof, I afix my signature hereto. I

CLARENCE A. BOLCOM. 

